JP2003281906A - Vehicle headlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, as to a conventional headlight of which a reflecting mirror swings according to operation of a steering wheel, an irradiated light swings by keeping its light distribution shape, so that the light distribution shape and illuminance changes much between when traveling straight and when turning, resulting in discomfort of a driver. <P>SOLUTION: Related to a vehicle headlight 1, a diffusion auxiliary lens 8 which vertically diffuses the reflection light which has transmitted is provided in the optical path of the reflection light from a parabolic mirror 7 which changes radiation direction according to the amount of operation with a handle. The diffusion auxiliary lens is so set that the amount of diffusion becomes smaller as the radiation direction shifts sideways from the front of a vehicle when the parabolic mirror 7 swings. When the vehicle advances straight, it is diffused wide to evenly illuminate the entire advancing direction for improved visibility, while when advancing a curved course, it illuminates bright around outlet of a curved course so that a course is easily confirmed. In addition, no significant illuminance difference is generated between both cases. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle headlight, and more specifically, is called a projector type.
For vehicle headlights that are configured by combining elliptical reflecting surfaces such as spheroids, shielding plates, and projection lenses,
It is an object of the present invention to provide a structure which can be improved in function as being more excellent in visibility when passing through a curved road.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No. 2001-229715 by the same applicant discloses a conventional vehicle headlamp of this type, and FIGS. In addition to the light distribution by the irradiating first elliptical reflection surface and the projection lens, a second elliptical reflection surface and a parabolic reflection surface having the second focal point of the second elliptical reflection surface as a focal point are provided. The parabolic reflection surface also produces reflected light when traveling on a straight road, and the parabolic reflection and the light distribution due to the reflected light from the first elliptical reflection surface. The passing light distribution is obtained by superimposing the light distribution by the reflected light from the surface.

When passing through a curved path, the parabolic reflection surface is rotated by the operation of a handle or the like with the second focus of the second elliptical reflection surface as the center of rotation, so that a parabola is formed. The direction of the reflected light from the system reflection surface is directed to the direction of the curved road that is going to proceed, whereby the vicinity of the exit of the curved road is illuminated brightly, and the visibility when passing through the curved road is improved.

[0004]

However, in the above-mentioned conventional vehicle headlamp, the light distribution by the reflected light from the first elliptical reflecting surface and the light distribution by the reflected light from the parabolic reflecting surface are provided. Since the light distribution when traveling straight is formed with the light, if the light distribution due to the reflected light from the parabolic reflection surface, which is a part of it, moves to the side, the front direction of the vehicle will change. It becomes dark, and there arises a problem that visibility on a road shoulder is deteriorated.

Also, in the light distribution in which the vicinity of the exit of the curved road is illuminated by the rotation of the parabolic reflection surface, it is a part of the passing light distribution as described above, and therefore the brightness is reduced. Is not enough, and overall speaking, the irradiation range is wide, but the illuminance tends to be insufficient in both the front direction and the course direction, and the effect of improving visibility as expected can be obtained. There was a problem that could not be obtained.

[0006]

The present invention is, as a concrete means for solving the above-mentioned conventional problems, a first light source having an optical axis in the irradiation direction of a headlight and a first focus being arranged on a light source. An elliptical reflection surface and a second elliptical reflection surface that arranges a first focus on the same light source and intersects the optical axis downward with the optical axis of the first elliptical reflection surface are provided. A projection lens and a shielding plate as required are provided corresponding to the second focus of the surface, and the second focus is set as the approximate focus and the optical axis is set to correspond to the second focus of the second elliptical reflection surface. A parabolic reflection surface that is substantially in the irradiation direction is provided, and the parabolic reflection surface is rotatable at least in the horizontal direction with the second focus of the second elliptical reflection surface as the approximate center of rotation. In a vehicle headlight, the reflected light transmitted through the parabolic reflection surface is spread horizontally in the optical path. An auxiliary lens for diffusion is provided, and the auxiliary lens for diffusion is set so that the degree of diffusion becomes smaller as the irradiation direction moves from the front side to the side of the vehicle by the rotation of the parabolic reflection surface. The problem is solved by providing a vehicle headlight characterized by:

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail based on the embodiments shown in the drawings. Reference numeral 1 in FIGS. 1 and 2
What is indicated by is a vehicle headlamp according to the present invention. The vehicle headlamp 1 includes a light source 2 having a center line X as an irradiation direction, and a spheroid having a first focus f1 set on the light source 2. A first elliptical reflection surface 3 that is an ellipse such as a compound ellipse, and a shield plate 4 provided near the second focus f2 of the first ellipsoid reflection surface 3.
The projector-type lamp including the projection lens 5 having a focal point in the vicinity of the shielding plate 4 as a basic configuration is the same as the conventional example.

In addition to the above, the first elliptic reflection is located at a position where it does not interfere with the optical path from the first elliptical reflection surface 3 to the projection lens 5 and can receive the direct light from the light source 2. Similarly to the surface 3, the light source 2 is set to the first focus (f1), and the long axis Y
Is intersected with the center line X downward, and the second focal point f62 is located, for example, below the first elliptical reflection surface 3, and a second elliptical reflection surface 6 is provided. A parabolic reflection surface 7 such as a rotating parabolic surface having the second focal point f62 of the two elliptical reflection surface 6 as a focal point and having a reflection direction substantially parallel to the central axis X is provided. It is also similar to the conventional example that it is rotatable about a substantially vertical line passing through the second focal point f62 as an axis Z.

Here, in the present invention, the parabolic reflection surface 7 is rotated, and a diffusion auxiliary lens 8 is provided in a range where the reflected light moves. The parabolic reflection surface 7 is rotated. When the vehicle is operated to turn right, for example, when the vehicle is operated to turn right, the parabolic reflection surface 7 provided on the vehicle headlamp 1 installed on the right side of the vehicle body reflects the reflected light. Is rotated substantially horizontally so that the direction of is directed to the right side. At this time, since the auxiliary lens 8 for diffusion is fixed to the vehicle body side, the light from the parabolic reflection surface 7 is gradually moved to the side. The position is changed to (right side) and the light is transmitted.

FIG. 3 shows the structure of the diffusion auxiliary lens 8. The lens cut 8a of the diffusion auxiliary lens 8 has a shape in which a plurality of cylindrical lenses with their axes in the vertical direction are in close contact with each other in the horizontal direction. It has a function of diffusing the reflected light from the parabolic reflection surface 7 in the horizontal (left and right) direction.

In the present invention, the lens cut 8a is used.
When the parabolic reflection surface 7 faces the front of the vehicle, the diffusion is widened at a wider angle, and the degree of the diffusion is weakened as the parabolic reflection surface 7 faces the side (for example, the right side) by operating the steering wheel or the like. That is, specifically, a cylindrical lens-shaped lens cut 8a having a relatively small radius is formed in a portion through which reflected light from the parabolic reflection surface 7 is transmitted while facing the front of the vehicle. A lens cut 8a in the shape of a cylindrical lens having a relatively large radius is formed in a portion where the reflected light from the parabolic reflection surface 7 in a state of facing the side is transmitted. In addition, reference numeral 9 in the drawing denotes an outer lens provided further in front of the auxiliary lens 8 for diffusion.

FIG. 4 shows the arrangement of the parabolic reflection surface 7 of the vehicle headlight 1 when the vehicle is traveling straight, and FIG. 5 shows the vehicle front provided with the auxiliary diffusion lens 8 described above. The light distribution characteristic Ds when the vehicle of the lamp 1 is traveling straight is shown, and this light distribution characteristic Ds is the first elliptic reflection surface 3 and the shielding plate 4.
And a projection lens 5 to form a light distribution characteristic D1, and a second elliptical reflection surface 6, a parabolic reflection surface 7 and a diffusion auxiliary lens 8 to form a light distribution characteristic Ds2. .

At this time, since the vehicle is in a straight traveling state, the parabolic reflection surface 7 also reflects light in the front direction of the vehicle,
As described above, the light distribution characteristic Ds2 is diffused at a wide angle by the diffusion auxiliary lens 8. Therefore, the light distribution characteristic Ds, which is the addition of the light distribution characteristic D1 and the light distribution characteristic Ds2,
As shown in FIG. 6, the front side of the front of the vehicle is widely illuminated to easily secure the field of view when traveling straight ahead. In addition, since the light distribution characteristic Ds2 is diffused at a wide angle, the road surface in front of the vehicle does not have a remarkably bright portion, and the deterioration of the far field which occurs when there is a bright road surface in front is also prevented.

FIG. 7 and FIG. 8 show the state and the light distribution characteristic Dc of the same vehicle headlight 1 when the vehicle is turning to the right. When the steering wheel or the like is operated, a parabolic reflection surface is shown. 7
Will produce reflected light that travels to the front right of the vehicle, that is, it will pass through the portion of the auxiliary lens 8 for diffusion that is provided with the lens cut 8a having a weak diffusion action.

Therefore, as shown in FIG. 7, the light distribution characteristic Dc2
Is the light distribution characteristic D1 that does not change when the steering wheel is operated.
As it moves to the right half, the diffusion angle changes to a narrow spot shape. Therefore, as shown in FIG. 9, when the road surface is illuminated, the vicinity of the exit of the curved road is illuminated brightly with the spot-shaped light distribution characteristic Dc2, which improves the visibility of the curved road and the front of the vehicle. A directional field of view can also be secured.

FIG. 10 shows another embodiment of the vehicle headlamp 1 according to the present invention. In this embodiment, the second elliptical reflection surface 16 substantially covers the front surface of the first elliptical reflection surface 3. In order to further improve the luminous flux utilization rate with respect to the light source 2, the second elliptical reflection surface 16 is provided with an opening 16a in a necessary portion at this time, and the second elliptical reflection surface 16 is provided with a shield plate 4 and a projection lens 5. The optical path may be secured, or may be divided into upper and lower parts so as to secure the optical path.

With this structure, the parabolic reflection surface 1
The amount of light from 7 naturally increases, and with it,
When the entire parabolic reflection surface 17 is rotated as described in the previous embodiment, the amount of light to be moved is large only by adjusting the diffusion degree with the auxiliary diffusion lens as in the previous embodiment. It will cause the driver to feel uncomfortable.

Therefore, in this embodiment, the parabolic reflection surface 1 is used.
By rotating only a part of 7 as the movable part 17a and fixing the other part as the fixed part 17b, it is possible to prevent a driver, a pedestrian, etc. from feeling uncomfortable because the amount of light does not move more than necessary. Are prevented.

At this time, the light source 2 is a so-called C-8.
In the case of having a filament having a length along the central axis X direction, which is called a mold filament, the movable portion 17a of the parabolic reflection surface 17 has a light source at the second elliptical reflection surface 16. If it is assumed that the reflected light from the portion near the front surface of 2 is received, it becomes easy to form a spot-like beam.

FIG. 11 shows still another embodiment of the vehicle headlamp 1 according to the present invention, which is a vehicle headlamp 1 of this type in recent years.
As for the design tendency, the outer lens 9 is often made transparent to produce a transparent feeling and a glittering feeling. At this time, if the diffusion auxiliary lens 8 is provided with the lens cut 8a, the diffusion auxiliary lens 8 loses transparency and the expected design effect cannot be obtained.

Therefore, in this embodiment, as shown in the figure, a diffusion auxiliary lens 18 which does not use a lens cut is provided, and in this diffusion auxiliary lens 18, the front surface 18 is provided.
a, that is, on the side viewed through the outer lens 9, a curved surface such as a parabola whose curvature changes in a horizontal section is adopted, and a curved surface having a constant curvature such as an arc surface is adopted for the rear surface 18b. There is.

The portion of the front surface 18a having the largest curvature is matched with the position of the parabolic reflection surface 7 when the vehicle goes straight. By doing so, the widest diffusion angle in the horizontal direction can be obtained when the vehicle goes straight, and the diffusion angle in the horizontal direction gradually decreases according to the operation amount of the steering wheel or the like, which was described in the previous embodiment. The same effect as the auxiliary lens 8 for diffusion can be obtained, and the transparency can be secured.

[0023]

As described above, according to the present invention, the transmitted reflected light is horizontally diffused in the optical path of the reflected light from the parabolic reflection surface that changes the irradiation direction according to the operation amount of the handle or the like. A vehicle is provided with a diffusing auxiliary lens, and the diffusing auxiliary lens is set such that the degree of diffusing decreases as the irradiation direction moves from the vehicle front side to the side by the rotation of the parabolic reflection surface. As a vehicle headlight, when the vehicle goes straight, the light from the parabolic reflection surface is widely diffused by an auxiliary lens for diffusion to uniformly illuminate the entire traveling direction, improving visibility and passing through curved roads. Sometimes the same auxiliary diffusion lens is used to brightly illuminate the vicinity of the exit of the curved road to make it easy to confirm the course, and there is no extreme difference in illuminance on the road surface between when going straight and when passing through the curved road. Uncomfortable to the driver as a thing It shall also not cause, have, in which exhibits the excellent effect in improving the performance of a vehicle headlamp of this type.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a vehicle headlamp according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a horizontal sectional view showing the structure of a diffusion auxiliary lens.

FIG. 4 is a cross-sectional view taken along the line BB of FIG. 1 showing a state when the vehicle goes straight ahead.

FIG. 5 is an explanatory diagram showing a light distribution characteristic when a vehicle goes straight.

FIG. 6 is an explanatory diagram showing an irradiation state of a road surface when a vehicle goes straight.

FIG. 7 is a cross-sectional view taken along the line BB in FIG. 1 showing a state when the vehicle is turning.

FIG. 8 is an explanatory diagram showing a light distribution characteristic when the vehicle is turning.

FIG. 9 is an explanatory diagram showing a road surface irradiation state when the vehicle is turning.

FIG. 10 is a sectional view showing another embodiment of the vehicle headlamp according to the present invention.

FIG. 11 is a cross-sectional view showing a main part of still another embodiment of the vehicle headlamp according to the present invention.

[Explanation of symbols]

1 ... Vehicle headlight 2 ... Light source 3 ... First elliptical reflection surface 4 Shield plate 5 ... Projection lens 6 …… Second elliptical reflective surface 7: Parabolic reflection surface 8, 18 ... Auxiliary lens for diffusion 8a: Lens cut 18a …… 18b …… 9 ... Outer lens

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Claims (2)

[Claims] 1. A first ellipsoidal reflecting surface having an optical axis in the direction of irradiation of a headlight and having a first focus on a light source, and a first focus on the same light source with the optical axis being the first ellipse system. A second elliptical reflection surface that intersects the optical axis of the reflection surface downward is provided, and a projection lens and a shield plate as necessary are provided corresponding to the second focus of the first elliptical reflection surface, Corresponding to the second focal point of the second elliptical reflection surface, a parabolic reflection surface having the second focus as a substantially focal point and the optical axis as a substantially irradiation direction is provided, and the parabolic reflection surface is the first focal point. In a vehicle headlamp that is rotatable at least in the horizontal direction with the second focal point of the two elliptical reflection surfaces as the approximate center of rotation, in the optical path of the reflected light from the parabolic reflection surface. A diffusion auxiliary lens for diffusing the reflected light in the horizontal direction is provided, and the diffusion auxiliary lens rotates the parabolic reflection surface. Is set so that the degree of diffusion decreases as the irradiation direction moves from the front of the vehicle to the side. 2. The parabolic reflection surface is divided into two, one of which rotates so that the diffusing lens is effective for at least the reflected light on the rotating side. The vehicle headlamp according to claim 1, wherein the headlight is set to.